if_extract.inc

#if defined _INC_if_extract
	#endinput
#endif
#define _INC_if_extract

/*

88888888888                                                            88
88                                                                     88
88                                                                     88
88aaaaa      8b,     ,d8  ,adPPYYba,  88,dPYba,,adPYba,   8b,dPPYba,   88   ,adPPYba,  ,adPPYba,
88"""""       `Y8, ,8P'   ""     `Y8  88P'   "88"    "8a  88P'    "8a  88  a8P_____88  I8[    ""
88              )888(     ,adPPPPP88  88      88      88  88       d8  88  8PP"""""""   `"Y8ba,
88            ,d8" "8b,   88,    ,88  88      88      88  88b,   ,a8"  88  "8b,   ,aa  aa    ]8I
88888888888  8P'     `Y8  `"8bbdP"Y8  88      88      88  88`YbbdP"'   88   `"Ybbd8"'  `"YbbdP"'
                                                          88
                                                          88

*/

#if 0

IF_EXTRACT__ (new a, b, string:c[128]; params)
{
	// Parameters all found.
}
else
{
	// Something missing.
}

new params[54];
if_extract(new a, b, string:c[45], d[5]; params)
{
}

// Pre-declare variables.
new a, b, string:c[45], d[5];
if_extract(a, b, string:c[45], d[5]; params)
{
}

// Defaults.
if_extract(new player:ps[5], hex:e = 7; params)
{
}

#endif

/*

88b           d88
888b         d888
88`8b       d8'88
88 `8b     d8' 88  ,adPPYYba,   ,adPPYba,  8b,dPPYba,   ,adPPYba,
88  `8b   d8'  88  ""     `Y8  a8"     ""  88P'   "Y8  a8"     "8a
88   `8b d8'   88  ,adPPPPP88  8b          88          8b       d8
88    `888'    88  88,    ,88  "8a,   ,aa  88          "8a,   ,a8"
88     `8'     88  `"8bbdP"Y8   `"Ybbd8"'  88           `"YbbdP"'

*/

// Not the normal `__gOnce` method here, but still works.  The other is only limited by the fact
// that `__once` is in the middle part of the loop.  We have the whole loop to play with here.
#define IF_EXTRACT__(%1;%0) for(EXTR@:(__gOnce=0);EXTRP:%1;!__gOnce++)if(!unformat(_:EXTRT:EXTRU:%0,#,%1,,))

#define EXTRP:%9;%1) %1;)
#define EXTR@:%9;EXTRP:new%1;%9)if(%3(%4,#,new%5) new%1;__gOnce++;__gOnce=0)if(%3(%4,#,%5)
#define EXTRT:EXTRU:%0<%3>%4#,%1,%2) EXTRY:%0%4#P<%3>,|||%1|||%2)
#define EXTRU:%0#,%1,%2) EXTRY:%0#,|||%1|||%2)

/*

    88                                                                       88
    88                ,d                                                     88
    88                88                                                     88
    88  8b,dPPYba,  MM88MMM  ,adPPYba,  8b,dPPYba,  8b,dPPYba,   ,adPPYYba,  88
    88  88P'   `"8a   88    a8P_____88  88P'   "Y8  88P'   `"8a  ""     `Y8  88
    88  88       88   88    8PP"""""""  88          88       88  ,adPPPPP88  88
    88  88       88   88,   "8b,   ,aa  88          88       88  88,    ,88  88
    88  88       88   "Y888  `"Ybbd8"'  88          88       88  `"8bbdP"Y8  88

*/

// Everything below here is just useful extra stuff.  It doesn't actually enable parts of the
// `IF_EXTRACT__` macro, just does things like fix "extract" and defines `__once`.

#tryinclude <sscanf2>

// This macro enables the `#if YSI_KEYWORD()` check below.  It just looks for definitions
// controlling the addition of new keywords.  Note that the metion of `YSI` here is just an pre-
// existing convention.  This isn't actually part of YSI.
#define YSI_KEYWORD(%0) ((defined YSI_COMPATIBILITY_MODE && defined YSI_KEYWORD_%0) || (!defined YSI_COMPATIBILITY_MODE && !defined YSI_NO_KEYWORD_%0))

// Fix a bug in the original `extract`.
#if !defined EXTR1
	#error Include <sscanf2> before <if_extract>.
#endif
#undef EXTR1
#define EXTR1:EXTR2:EXTR3:EXTR4:%0#%1,%2|||%3[%7]|||%4) __EXTRW:%0#%1,%2|||%3[%7]|||%4)

// Define `if_extract` unless:
//
//   1) `YSI_COMPATIBILITY_MODE` is defined and `YSI_KEYWORD_if_extract` is NOT.
//   2) `YSI_COMPATIBILITY_MODE` is NOT defined and `YSI_NO_KEYWORD_if_extract` is.
//
// Otherwise only `IF_EXTRACT__` exists.
#if YSI_KEYWORD(if_extract)
	#define if_extract IF_EXTRACT__
#endif

// `__once`.  A useful "variable" that ensures a `for` loop only runs once.  This allows us to use
// the loop purely for its scoping abilities and not its repetition abilities.
#if !defined __once
	#define __once%1;%0) (__gOnce++)%1;(%0),__gOnce=0)
	#define __gOnce++)%1;(), __gOnce++)%1;
	stock __gOnce = 1;
#endif

#define for(IF_FAIL:new|||%1;%2) for(IF_PASS:new %1=%2;%1;)

#define IF_FAIL:new%0|||%1;%2)%8() ;__once;)%8(new%0 %1=%2 PP_RIGHT_BRACKET<>
#define IF_PASS:%3;%4;%9)%8() %3;__once;)%8(%4 PP_RIGHT_BRACKET<>

// `if (new a = b)` and `if (new a = b; cond)`.
#define IF__(new%0\32;%1=%2) for(IF_FAIL:new%0|||%1;%2)if()

#if YSI_KEYWORD(if)
	#define if(new%0\32;%1=%2) for(IF_FAIL:new%0|||%1;%2)if()
#endif

// `switch (new a = b)` and `switch (new a = b; cond)`.
#define SWITCH__(new%0\32;%1=%2) for(IF_FAIL:new%0|||%1;%2)switch()

#if YSI_KEYWORD(switch)
	#define switch(new%0\32;%1=%2) for(IF_FAIL:new%0|||%1;%2)switch()
#endif

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